Acid monoazo dyestuffs



United States Patent ACID MONOAZO DYESTUFFS Markus Kappeler, Basel, and Franz Frisch, Arlesheim,

Switzerland, assignors to Sandoz A.G., Basel, Switzerland, a Swiss firm No Drawing. Application March 31, 1958 Serial No. 724,868

Claims priority, application Switzerland April 9, 1957 7 Claims. (Cl. 260-199) This invention relates to acid monoazo dyestuifs of the general formula NH-R S og-R5 wherein R has the above-named meaning, z represents a chlorine atom or a methyl group, R represents an alkyl radical containing at least 6 carbon atoms, an alkoxyethyl or a phenoxyethyl radical and R represents a hydrogen atom, when R is an amino group which may be substituted, and a hydrogen atom or a 2',6'-dimethyl or a 2',4',6'-trimethylphenyl radical, when R is a hydroxy group.

The process for the production of the new acid monoazo dyestuffs consists in coupling in acid medium 1 mol of the diazo compound of an amine of the general formula 1/ 11 1 wherein x, y and R possess the above-cited meanings, with 1 mol of a coupling component of the general formula NH-R.

wherein R and R possess the afore-cited meanings.

The new acid monoazo dyestuflis of Formula I possess good building-up properties on wool, silk, leather and polyamide fibers. From neutral to weakly acid baths they yield dyeings or printings with shades ranging from scarlet to red-violet. The brightest and most yellowish red shades are obtained with the 2-amino-8-hydroxynaphthalene-G-sulfonic acid itself and its amides, employed preferably in combination with the diazo components of Formula III which contain 2 methyl groups in the 2,2 positions of the diphenyl radical, these components being especially valuable for this purpose. Contrastingly, the monoazo dyestuifs of the 2-arylamino-8- hydroxynaphthalene-G-sulfonic acids coming with the scope of the invention yield bluish red to red-violet shades. The dyeings invariably possess very good fastness to light and good to very good fastness to acids, alkali, chlorine, stoving, crocking, carbonizing and dry cleaning. They are also dischargeable and reserve viscose filament yarn, acetate, triacetate and polyethylene terephthalate fibers. Their wet fastness properties (i.e. the fastnesses to water, sea-water, washing, alkaline milling and perspiration) are good to very good, provided the molecular weight of the dyestutf used is greater than 600. To obtain good wet fastness properties the 2-amino-8- hydroxynaphthalene-fi-sulfonic acid, for example, must be coupled with a diazo component of Formula III containing a high molecular acyl radical. The higher molecular coupling components of Formula IV, in which the amino and/or sulfonic acid group is substituted, already yield monoazo dyestuffs of good to very good wet fastness on coupling with the simple acetyl derivatives of Formula III. As would be expected, those monoazo dyestuffs which contain a coupling component with a closed sulfonic acid group and thus have only the one solubilizing sulfonic acid group of the diazo component, show particularly good fastness to washing, perspiration and milling.

The amines of Formula III which are employed as starting materials in the present invention can be produced from the corresponding 4,4'-diamino-l,l'diphenylcompounds, for example 4,4'-diamino-1,l'-diphenyl-S- sulfonic acid, 4,4'-diamino-2,2-dimethyll,1'-diphenyl-S- sulfonic acid, 4,4-diamino-3,3-dimethyl-l,l' diphenyl-5- sulfonic acid, 4,4'-diamino-2,2'-dimcthoxy-1,l'-diphenyl- S-sulfonic acid, 4,4-diamino-2,2'-di-(trifiuoromethyl)-l, l'-diphenyl-5-sulfonic acid, 4,4-diamino-2,2'-di-(methylsulfonyl)-l,l-diphenyl-5-sulfonic acid, 4,4-diamino-3,3, 6,6'-tetramethyl-l,1'-diphenyl-5-sulfonic acid or 4,4'-diamino-2,2'-dichloro-1,1'-diphenyl-S-sulfonic acid.

Acylating is carried out in the normal way by treating the aqueous solutions of the alkali metal salts of these diaminesulfonic acids with aliphatic, cycloaliphatic, araliphtic, aromatic or heterocyclic acid anhydridm or acid chlorides; normally only the free amino group which is not in ortho-position to the sulfonic acid group is acylated by the treatment. Besides acetic anhydride, propionic anhydride, etc., other examples of suitable acylating agents are the chlorides of acetic acid, chloroacetic acid, propionic acid, chloropropionic acid, butyric acid, valeric acid, caproic acid, caprylic acid, Z-ethyI-caproic acid, capric acid, lauric acid, palmitic acid, oleic acid, stearic acid, butylglycoloxyacetic acid, phenoxyacetic acid, the cresoxyacetic acids, benzoic acid, monoand dichlorobenzoic acids, 4-tert.-butylbenzoic acid, phenylacetic acid, cyclohexaneor furancarboxylic acid. Particularly valuable as acylating agents are the chloroformic acid esters of various aliphatic, cycloaliphatic, araliphatic and heterocyclic-aliphatic alcohols, e.g. those of ethyl, 2- chloroethyl, butyl, hexyl, octyl, decyl, lauryl or cetyl alcohol, and the chloroformic acid benzyl, cyclohexyl, furfuryl, tetrahydrofurfuryl or morpholylethyl esters. Excellent alkylating agents are the chloroformic acid esters of certain ether alcohols, for example those of the ethylene glycol monoethyl, -butyl, -hexyl, octyl or -phenyl ethers, and of the diethylene glycol monomethyl, -butyl or-pheny e ters.

S it ble c uplingcomponents or Formula IV as here 816 Lammoiiydmynaphthaleno 6 sulfonic add itselt an its derivatives closed in the sulfonic acid group by n amide radical. The latter are obtained according to the known method by reacting Z-acetylaminosshydroxynaphthalene-ti'sulfonic acid chloride with ammania or a primary or secondary amine, with subsequent Splitting off of the acetyl group, for example, the amide, methylamide, dimethxlamide, ,B-hytdroxyethylamide, d1- tah vll-amide, morphclide, phenylamide, N- metbyl-Nphenylamide, N-cthyleNaphenylamide, N-fi-hyyethy -pheny cmide f l amino-ii-hydroxynaphthalcne-fi-sulfonic acid, Further suitable coupling compouents are the Z-phenylamiwB-hydroxynayahthalene-6-sulfonic acids with a phenyl radical substituted in the 2'- position, e.g. 2e(2'-methyl)-phenylamino-, 2-(2-methoxyrp env amine, zdz'chlc orc y dimethyh phenylamino or 2-(2',5'-dimethyl)-phenylamino-, but prefierahly the 2-(2,6'-di.methy1) -phenylamino and the 2(2',4',.6'-tri.methyl)-phenylammo-8-hydroxyl phthalenwt-sulfonic acid.

The starting materials of Formula III used in the presout process are indirectly diazotized. The diazo compounds are obtained in most cases as well crystallized precipitates of intense yellow or orange color: the yield is practically quantitative, so that they can be filtered off Without loss. After filtering off and dispersing in water at Ill-20 C. with a small addition of a mineral acid, the diazo compound is mixed with the acidified solution or suspension of the coupling component. Due to the hlgl'l energy of coupling displayed by the diazo compounds used in the process, the reaction proceeds fairly rapidly even in presence of mineral acid and invariably in the 1 position of the azo component. Notably high coupling ability, even in miner l aci solution, i exhibited y 2-phenylamino-8hydroxynaphthalene 6 sulfom'c acids used in the process. The coupling reaction can be accelerated by careful dropwise addition of a sodium acetate solution to efiect partial neutralization of the mineral acid. 0n formation of the product, common salt may be added. The dyestuffs. which are well crystallized in some cases, are filtered ofi and dried.

An advant geous method of performing the process, above all in the of monoazo dyestuffs closed with high molecular acyl radicals, is to use as starting materials the monoacetyl derivatives of Formula III which are obtained in a yield almost equal to the theoret1- cal yield. After diazotizlng, the resultant diazo compounds are coupled with the coupling components of Formula IV. The a e yl group is eliminated by sapomfication and the free amino group is then closed with the higher molecular acyl radical by one of the known methods.

In the following examples the parts and percentages are by weight and the temperatures in degrees centigrade.

EXAMPLE 1 35.6 parts of the sodium salt of 2,2-dimethyl-4-amino- 4'-acetylamino-1,l' dipl1cnyl-5-sulfonic acid and 7 parts of sodium nitrite are dissolved in 300 parts of water. The solution is run slowly into a mixture of 30 parts of concentrated hydrochloric acid and 100 parts of water with ice added to the diazotizing temperature at -l0. The diazo compound is precipitated as yellow crystals, filtered 0E and dispersed in 100 parts of icewater with stirring. The diazo suspension is mixed with 32.8 parts of Z-aminm8-hydroxynaphthalene-6-sulfon1c acid-N-methyl-Nsphenylamide dissolved in 400 parts of water and 10 parts of concentrated hydrochloric acid. By rapid cooling the hydrochloride is partially r e precipitated in finely divided .form- Couplin ls imitated immediately and is completed in the space of 4 to 5 hours by the dropwise addition of a solution of 30 parts of crystallized sodium acetate. On completion of coupling the monoazo dyestuff, already largely precipitated, is completely precipitated by an addition of common salt and is subsequently filtered off. The precipitate is freed from the adhering mother liquor by washing with a 2% common salt solution. The dried dyestuff is a red powder which dissolves in warm water to give a bright red solu tion, and in concentrated sulfuric acid a violent solution. It dyes wool, silk, leather and polyamide fibers from weakly acetic acid baths in full red shades of very good fastness to light, washing, perspiration and milling.

EXAMPLE 2 47.6 parts of 2,2'-dimethyl-4-amino-4'-carbodecyloxyamino-l,l-diphenyl-5-sulfonic acid of the formula CH SO H are indirectly diazotized as described in Example 1. The suspension of the yellowish diazo compound is mixed with a weakly acetic acid solution of 23.9 parts of 2- amino-8-hydroxynaphthalene-6-sulfonic acid. Coupling begins immediately and is completed in the course of 3 to 4 hours by dropping in an aqueous solution of 40 parts of crystallized sodium acetate.

The monoazo dyestufi so formed is completely precipitatcd by the addition of common salt and then filtered off. On drying it is obtained as a red powder which dissolves readily in warm water with a bright red coloration. The solution of the dyestufi. is concentrated sulfuric acid is blue in daylight, but red-violet in incident artificial light. From neutral to weakly acetic acid baths the dyestufi? dyes wool, silk and polyamide fibers in bright red shades of very good light fastness and very good fastness to washing, perspiration and milling.

A suitable dyeing procedure is as follows:

parts of a wool fabric are entered into a dyebath at 40 which is composed of 5000 parts of water, 10 parts of anhydrous sodium sulfate and 1 part of dye stulf. The bath is heated to 100 in 15 minutes and maintained at this temperature for 30 minutes. Then 20 parts of a 10% aqueous acetic acid solution are added and dyeing continued at 100 for a further 30 minutes. During the dyeing process the evaporated water is constantly replaced. The Wool, dyed to a red shade, is removed, rinsed with water and dried.

EXAMPLE 3 33.3 parts of 2,2'-dichloro-4,4'-diamino-1,l'-diphenyl- 5-sulfonic acid are dissolved in 400 parts of water and 50 parts of 2/n sodium hydroxide solution. 10 parts of sodium bicarbonate are added to the solution, then in the course of the next 3 to 4 hours 20-22 parts of chloroformic acid n-octyl ester are dropped in with vigorous stirring until the starting material is no longer indicated. To the resultant solution of the monocarbo-octyloxyamino derivative are added 7 parts of sodium nitrite, and it is then allowed to run slowly into a mixture of 40 parts of concentrated hydrochloric acid and 200 parts of water which is maintained at 5-10. The yellow precipitated diazo compound is filtered off and dispersed in 200 parts of ice-water, to which is added a solution of 36 parts of 2-(2,4',6'-trimethyl)phenylarnino 8 hydroxynaphthalene-6-sulfonic acid in 200 parts of water showing a weakly acid reaction on Congo red indicator paper. In the course of the next 4 to 5 hours a solution of 30 parts of crystallized sodium acetate in 200 parts of water is added dropwise to the coupling mass. On completion of coupling the precipitated monoazo dyestufr" is filtered off, washed With a 2% solution of common salt, and dried. It is a dark red powder which dissolves in warm water 7 EXAMi'LE 87 58.4 parts of the monoazo dyestufi obtained by acetic acid coupling of the diazo compound of 4-amino4'-acetylamino 2,2 dimethyl 1,1 diphenyl S sulfonic acid with Z-amino-S-hydroxynaphthalene-6-sulfonic acid are dissolved at 80-90 in 800 parts of a 3% sodium hydroxide solution and maintained at this temperature until the acetyl group is split off. On cooling the solution is 8 EXAMPLE 2 0 Ha 301E NH 1 n a c ,.,H,,-o-c O-HN-OQN:

H, HO-

s 0,1! EXAMPLE 3 The dyestufi paste thus obtained is dissolved in 1000 parts of water and parts of sodium bicarbonate at 20-25 and 22.5 parts of chloroformic acid decyl ester are added dropwise in the course of 34' hours to the well stirred solution. After several hours continued stirring the dyestutf is precipitated with common salt, filtered off and dried. It is identical with the dyestufi of Example 2.

With poorly soluble dyestuffs the acetyl group is saponified preferably in the presence of a water-soluble solvent like pyridine or ethyl alcohol.

Formulae of representative dyestuffs of the foregoing examples are as follows:

EXAMPLE 1 CH; SO3H 11TH:

1;, H0 CH weakly acidified and the precipitated dyestufl is filtered EXAMPLE 27 CH3 5 03H NH! C H EXAMPLE 32 C O: S 0 3H NH N=N H EXAMPLE 34 C B S O H N Hg 0 3NH 0 H Having thus disclosed the invention what is claimed ISI 1. An acid monoazo dyestufl? which has a molecular weight greater than 600 and corresponds to the formula wherein each of x and y stands for a member selected from the group consisting of a hydrogen atom, a chlorine atom, a methyl group, a methoxy group, a trifluoromethyl group and a methylsulfonyl group, R stands for a member selected from the group consisting of an alkyl group, a halogenated alkyl group, an alkoxyalkyl group, an alkoxy group, an alkoxyalkoxy group, an alkoxyalkoxyalkoxy group, a phenoxyalkoxy group, a cycloalkyl group, a cycloalkoxy group, an aralkyl group of the benzene series, an aralkoxy group of the benzene series, an aryl group of the benzene series, an alkoxyaryl group of the benzene series, a chlorinated aryl group of the benzene series, a pyridyl group, a morpholinoethoxy and a tetrahydrofurfuryloxy group, R stands for a member selected from the group consisting of a hydroxy group and a 9 10 primary, secondary and tertiary amino group, and R radical, R stands for a member selected from the group stands for a member selected from the group consisting consisting of a hydrogen atom, a 2,6-dirnethylphenyl of a hydrogen atom and a phenyl radical carrying at radical and a 2',4',6'-trimethylphenyl radical, when R, least in one of its orthopositions a member selected from represents a hydroxy group and stands only for a hydrothe group consisting of lower alkyl and lower alkoxy 5 gen atom, when R, has another meaning. groups and a chlorine atom, when R represents a hy- 3. The acid monoazo dyestufi which corresponds to droxy group, and only a hydrogen atom, when R, has the formula another meaning.

2. A monoazo dyestutf which corresponds to the Cm 5013 formula 10 2 50,11 NH-R, u-C H 0O0HN N=N MMHNGQM H. no

I H0 15 01H Born 4. The acid monazo dyestufi which corresponds to wherein z stands for a member selected from the group the formula C] 501E NH OH: WEPMHNGQM H.

consisting of a chlorine atom and a methyl group, R 5. The acid monoazo dyestufi which corresponds to stands for a member selected from the group consisting the formula of a hydroxy group and a primary, secondary and ter- 6. The acid monoazo dyestufi which corresponds to tiary amino group, R stands for a member selected from the formula CgH on. 80,]: NH n -c.rn,-o-o,n.-o-c O-HNQ-N=N n,

H, no

the group consisting of an alkyl radical containing 6 to 18 7. The acid monoazo dyestufi which corresponds to carbon atoms, an alkoxyethyl radical and a phenoxyethyl the formula 80H N OQ a, no

Og-NH-Og a References Cited in the file of this patent UNITED STATES PATENTS 1,201,544 Bergdolt Oct. 17, 1916 2,374,157 Kvalna Apr. 17, 1945 2,831,850 Merian et al. Apr. 22, 1958 UNITED STATES PATENT OFFICE Certificate of Correction Patent No. 2, ,548 September 15, 1959 Markus Kappeler et :11.

It is hereby certified that error appears in the printed specification of the above numbered atent requiring correction and that the said Letters Patent should read as correcte below.

Column 4, line 34, for is concentrated read -in concentrated; column 7, line 55, for 3- read -3-4:; column 8 Example 32 the extreme left-hand portion of the formula should appear as shown beiow instead 0 as in the patent:

column 10, claim 5, the lower right-hand portion of the formula should appear as shown below instead of as in the patent:

Ce I same column 10, claim 7, the lower right-hand portion of the formula should appear as shown below instead of as in the patent:

AOr-NE-Jhfl Signed and sealed this 24th day of May 1960.

Attest: KARL H. AXLINE, Attesting Oficer.

ROBERT C. WATSON, aomnileioner of Patmtl. 

1. AN ACID MONOAZO DYESTUFF WHICH HAS A MOLECULAR WEIGHT GREATER THAN 600 AND CORRESPONDS TO THE FORMULA 